DESCRIPTION: (Candidate's Abstract) The specific aims of this proposal are as follows: to train Dr. Nichols in the areas of visual epidemiology and biostatistics, to evaluate the systemic and environmental factors associated with dry eye in the Women's Health Initiative Observational Study, and to investigate the relations among dry eye diagnostic tests in this cohort. We plan to utilize the Observational Study (OS) cohort of the Women's Health Initiative (WHI) at The Ohio State University. Approval for this WHI ancillary study has been obtained from the WHI Executive Committee and the WHI Design and Analysis Committee. In an effort to increase statistical power, a dry eye screening survey will be used to enrich the dry eye cases in this cross-section study design (sometimes called a prevalent case-control study). Following the dry eye screening survey, a dry eye examination will be performed on approximately 750 WHI Observational study participants (350 symptomatic patients, and 400 asymptomatic patients frequency matched by age). The definition of dry eye we will use includes the presence of symptoms of ocular irritation and one of three abnormal dry eye diagnostic tests: tear break-up time, fluorescein staining of the cornea, and measurement of tear meniscus height. Logistic regression will be used to assess the factors associated with a dry eye diagnosis using baseline and year3 follow-up data from the Women's Health Initiative Observational Study cohort. Sensitivity and specificity and Receiver Operating Characteristic (ROC) analyses will be performed to evaluate the relations between the additional diagnostic tests performed in the dry eye examination (osmolality, lactoferrin concentration, phenol red thread test, and lissamine green conjunctival staining) and our proposed definition of dry eye. The training plan and the research plan are closely related in this proposal. The research plan will produce a data set of adequate scope and size to allow Dr. Nichols to apply the epidemiologic and biostatistical theory learned in the classroom. Throughout the course of the training plan, Dr. Nichols will complete the Ph.D. program in Vision Science/Physiological Optics and the Master's in Public Health program with an emphasis in epidemiology and biostatistics at The Ohio State University. Together, the research plan and the training plan will provide Dr. Nichols with the skills and experience needed to excel as a patient-based clinician-scientist.